TopHat is a fast splice junction mapper for RNA-Seq reads. It aligns RNA-Seq reads to mammalian-sized genomes using the ultra high-throughput short read aligner Bowtie, and then analyzes the mapping results to identify splice junctions between exons. TopHat is a collaborative effort between the Institute of Genetic Medicine at Johns Hopkins University, the Departments of Mathematics and Molecular and Cell Biology at the University of California, Berkeley and the Department of Stem Cell and Regenerative Biology at Harvard University. A recommended dependency is bowtie2.